Adhesive compositions based on polyhydroxyl compounds and polyisocyanates are known. See, e.g., U.S. Pat. Nos. 3,718,518, 3,755,222, 3,812,003, 3,886,122, 3,935,051, and 4,487,909. It is also known to produce adhesive compositions from isocyanate-terminated prepolymers which are moisture curable (see, e.g., U.S. Pat. Nos. 3,779,794, 4,323,491, 4,750,963, and 4,835,012) or which are further reacted with amines (see, e.g., U.S. Pat. Nos. 4,156,064 and 4,336,298).
It is also known to formulate non-sagging polyurethane structural adhesives using primary or secondary amines, polyhydroxyl compounds and polyisocyanates. See, e.g., U.S. Pat. Nos. 3,714,127, 3,979,364, 4,444,976, 4,552,934, 4,728,710, and 4,743,672, and U.S. application Ser. No. 07/076,951 filed on Jul. 23, 1987. Upon cure, such non-sagging compositions show a high degree of contraction (i.e., shrinkage). When used to bond or repair plastic parts, this can result in deformation of the plastic part. In the case of solid substrates, e.g., a crack in concrete, contraction of the adhesive composition may lead to disbonding on the interface or formation of cracks. One way to solve this problem has been to use high amounts of inorganic fillers such as calcium carbonate, talc, barium sulfate and the like. These filled systems, however, are usually highly viscous and difficult to mix and to pump. Additionally, the fillers must be carefully dried before use to avoid foaming which would result in a weakening of the adhesive bond. The problems associated with manufacturing non-sagging polyurethane adhesives are described, e.g., in U.S. Pat. Nos. 3,755,222, 3,886,122, 3,935,051, 4,444,976 and 4,728,710.
It is known that polyurethane compositions can be used to seal and strengthen water-bearing geological formations. See, e.g., U.S. Pat. No. 4,454,252.
Polyurethane compositions which cure in the presence of moisture with an increase in volume have been described in U.S. Pat. No. 4,489,176. The compositions described consist broadly of an isocyanate terminated prepolymer, a foam stabilizer, and diluents. The diluents described are organic solvents and include fluorochlorocarbons.